The+Chemistry+of+Water



Water is the most abundant molecule on Earth, and is the only molecule that naturally exists as a solid, liquid, and as a gas. Water is a covalently bonded molecule, which means it has a positive charge on one end and a negative charge on the other end. It is also called a polar molecule, or dipole molecule. The water molecule is also an asymmetrical molecule with two hydrogen atoms at one end of the oxygen molecule which doubles the strength of the dipole.

There are many dipole molecules, and hydrogen combines with many different atoms to produce gaseous compounds. However, hyrogen only forms a liquid compound when it combines with oxygen because of the strong electronegativity of the oxygen atom.

Remember that a hydrogen atom only has one electron and when it is pulled into the more electronegative oxygen atom, the positive nucleus of the hydrogen atom becomes exposed to form the dipole. The positively charged hydrogen end of the water molecule also attracts the negatively charged end of other water molecules. This attraction is called a hydrogen bond and gives the water molecule its unique characteristics. The U.S. Geologic Survey has collected many resources about water and organized them on their website specifically for school use. Spend some time navigating the site to view pictures, read about current issues and opinions, view maps and data; and visit the interactive center.

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